More particularly, the embodiments of the present invention relate to a writing implement comprising:
a body which extends longitudinally along a central axis Z, the body having a first end and second end;
an ink reservoir; and
and a roller having an outer writing surface, the roller being located at one of the ends of the body, connected to the ink reservoir and mounted so as to be able to rotate around a primary axis.
This type of writing implement is particularly well suited to highlighter pens, owing to the width and speed of marking it allows. It can also be used to apply a pattern or a repetitive decorative message.
As described in document U.S. Pat. No. 3,085,554, a writing implement of the type described above comprises a cylindrical writing roller which, when the writing implement is used, turns on itself around an axis perpendicular to the central axis of the body.
The writing roller of an embodiment of the present invention comprises hemispherical ends guided by rounded cavities which allow limited angular movement around the central axis of the body of the writing implement, in order to produce lines of varied thickness. The thickness of the lines depend on the angle at which the user chooses to hold the body, the direction of writing and the angle of the writing roller with respect to this direction. The writing implement of an embodiment of the present invention produces a line of maximum thickness when the axis of the roller is perpendicular to the direction of writing and parallel to the writing surface.
However, if the body of the implement is tilted in a plane normal to the direction of writing, for example when the user naturally tilts the pen toward him, the roller is no longer parallel to the sheet and only one end of the roller is in contact with it.
Roller-type writing implements are thus generally not very comfortable to use, especially when the user wants to draw a horizontal line of writing of maximum thickness.